However, I needed some help from the folks on the Raspberry Pi forums to get it connected to the network, but once that was sorted out it worked very nicely and I had no issues connecting between machines using either DeCNET or LAT.

Running one virtual VAX on my Raspberry Pi was quite cool, but what I really wanted to do was to be able to network multiple virtual VAXen on my desktop – and I have now have finally figured out how to do it.

Note – Since SIMH and QEMU both allow you to use tap devices this solution should work for both.

To install the additional packages required you need to be logged in as root.

$ su
Password:

OR

$ sudo -i
Password:

Installing required packages

The additional packages we need are the same as those needed on the Raspberry Pi, with the addition of libpcap-dev which is used by simh (and needed to compile it from source).

Configuring the network

To allow the virtual machines to connect to the physical network we need to create an ethernet bridge (br0) to allow the linux host to connect to the physical interface (eth0), and a separate TUN/TAP network interfaces for each virtual machine (tap0, tap1), bridging these to the physical interface allows each virtual machine to connect to the network. The key to getting this to work was realizing that the ethernet bridge could bridge more than just two interfaces.

Note – You will need to substitute the username of the user that will be running simh for <username> .

Now all I have to do is remember how to build a Local Area VAX Cluster, with multiple satellite nodes booting of a VAX server (actually I want to build a mixed LAVC with multiple versions of VMS running from multiple system disks!) – that should keep me busy for a while.